Our partner

Analog laser power probes

From Macken

Each power probe is a self-contained unit consisting of an absorbing head, a temperature measuring mechanism, a zeroing knob and a readout dial. In operation, the dial is zeroed. Then the absorbing head on the end of the Power Probe is exposed to the laser beam for a specified time interval. After the Power Probe has been removed from the laser beam, the average laser power can be read out on the dial. The process takes about one minute. If it is necessary to make several power measurements in succession, the absorbing head can be rapidly cooled by immersing in a beaker of water between measurements.

Features

Conveniently size of absorbing head
One minute to make a laser power measurement
Very tough absorbent coating
Easy zero adjustment mechanism
Long-life all-metal construction

Specifications

Accuracy [%] for all ±5

Repeatability [%] for ±1.5

Model	Power Range [W]	Demage Thershold [W/cm²]	Exposure Time [s]	Division [W]	Absorbing Head [cm]	Length [cm]	Weight [g]
P20Y	0-20	3000	30	0.2	4.58 x 2.54	22	89
P50Y	0-50	3000	20	0.5	4.58 x 2.54	22	98
P100Y/	0-100	3000	20	1	5.08 x 3.18	22	120
P100C	0-100	10000	20	1	5.08 x 3.18	22	120
P200Y	0-200	2500	20	2	5.08 Ø	22	157
P200C	0-200	7000	20	2	5.08 Ø	22	157
P500Y	0-500	2000	20	5	5.08 Ø	22	183
P500C	0-500	4000	20	5	5.08 Ø	22	183
P1000Y	0-1000	1750	20	10	6.35 Ø	22	287
P1000C	0-1000	2500	20	10	6.35 Ø	22	287
P2000Y	0-2000	1200	20	20	7.62 Ø	22	522
P2000C	0-2000	1500	20	20	7.62 Ø	22	522
P4000Y	0-4000	900	20	25	8.89 Ø	28	753
P4000C	0-4000	1100	20	25	8.89 Ø	28	753
P10KY	0-5000 0-10000	750	20 10	50 100	8.89 Ø	28	1144
P10KC	0-5000 0-10000	900	20 10	50 100	8.89 Ø	28	1144
Wavelength for Y-Models: 900 - 1250 nm, Wavelength for C-Models 8 - 11 µm

Conical Laser Power Probes for high power density

Conical Head Power Probes are used to measure high power density CO₂ laser beams which may damage the standard flat surfaced Power Probes. The conical absorbing cavity exhibits a high heat dissipation.

There are three models of Conical Power Probes: C2K, C4K and C10K. Table 1 below gives specifications for these models. Table 2 gives approximate damage threshold for both the flat surface and conical power probes.

Conical Power Probe Specifications
Model	C2K	C4K	C10K
Primary Power Range [W]	0 - 2000 (20 sec)	0 - 4000 (20 sec)	0 - 10000 (10 sec)
Alternative Power Range [W]	-	-	0 - 5000 (20 sec)
Absorbing Head, Ø [cm]	6,2	7,0	7,6
Conus, Ø [cm]	5,08	5,7	6,35
Weight [g]	535	1000	1160
Accuracy [%]	±5%	±5%	±5%
Repeatability [%]	±1.5%	±1.5%	±1.5%

Explanation of Damage Threshold

High power lasers that can cut metal can also damage the absorbing head of a power probe if the beam is too concentrated. It has been found that it is not possible to quote a single number for the power density that will damage a power probe. The damage threshold is also a function of the total power in the beam and whether the absorbing head is moved during the exposure.

For a CO₂ laser, there is no loss in absorbtivity (no damage) when the coating is heated to the point where it exhibits a visible bleached spot but no other change. There is damage when metallic areas can be seen on the surface. In operation, power densities should be kept substantially below the indicated damage threshold.

Approximate Damage Threshold
Power in a CO₂ laser beam [W]	Exposure Time [s]	Flat Probes¹ [W/cm²]	Conical Probes² [W/cm²]
100	20	10000	15000
200	20	7000	11000
500	20	4000	8000
1000	20	2500	5000
2000	20	1500	3000
5000	20	1100	2200
10000	10	900	1800
¹ Model P500C, P1000C, P2000C, P10KC, H3C and H4C ² Model C2K, C4K and C10K